Flying object

ABSTRACT

In a flying object, a PCU has a plurality of operation modes in which an engine and/or a motor generator is used as a driving source for a pusher propeller. In accordance with the state of the flying object, the PCU controls the engine, a clutch, and the motor generator in one of the operation modes.

TECHNICAL FIELD

The present invention relates to a flying body (flying object) in whicha machine body thereof is propelled by a first propeller and made tofloat by a second propeller.

BACKGROUND ART

As an example, JP 2016-088110 A discloses that, by providing power froma battery to a plurality of electric motors to drive the electricmotors, a plurality of propellers are rotated to thereby cause amulticopter to fly.

SUMMARY OF INVENTION

However, the multicopter of the above publication does not have fixedwings. Therefore, the only operational mode of the multicopter is ahover mode. As a result, when this multicopter flies, the machine bodyefficiency is low and it is necessary to expend a greater amount ofenergy.

Furthermore, in the above publication, a power generator generateselectrical power by the output of the engine, and this generated powercharges a main battery. Therefore, there is low energy conversionefficiency when converting the engine output into electrical power usingthe power generator. Accordingly, compared to a flying body that fliesusing the engine output, the flying velocity is low and the flightdistance is short in the multicopter of the above publication. Yetfurther, when the motor or the like malfunctions, the multicopter cannotfly.

However, a flying body that flies by rotating a propeller with a motor,such as the multicopter in the above publication, has greatercontrollability than a flying body that flies using the engine output.Also, a flying body that flies using motor output creates less noisethan a flying body that flies using engine output. Also, a flying bodythat flies using motor output creates less noise than a flying body thatflies using engine output.

The present invention has been devised in order to solve this type ofproblem, and has the object of providing, a flying body that is capableof flying in an optimal operational state from the viewpoint of safety,noise, comfort, controllability, and cost, without requiring acomplicated configuration.

An aspect of the present invention is a flying body including a firstpropeller that propels a machine body and an electric second propellerthat causes the machine body to float. The flying body further includesan engine; a motor generator connected to the first propeller; a clutchthat connects and disconnects the engine and the motor generator; and acontrol section. The control section has a plurality of operationalmodes in which at least one of the engine and the motor generator actsas a drive source of the first propeller. The control section controlsthe engine, the clutch, and the motor generator, in accordance with oneoperational mode among the plurality of operational modes, depending onthe state of the flying body.

According to the present invention, the flying body includes the engine,the clutch, the motor generator, and the control section, and has ahybrid configuration in which at least one of the engine and the motorgenerator acts as the drive source of the first propeller. Furthermore,the control section has a plurality of operational modes, and connectsor disconnects the clutch in an optimal operational mode, according tothe state of the flying body.

Due to this, it is possible to make the flying body fly by controllingthe engine, the clutch, and the motor generator in the operational modethat is optimal from the viewpoints of safety, noise, comfort,controllability, and cost. As a result, it is possible to realize aflying body with a high degree of freedom of control adaptable tovarious situations, without adopting a complicated configuration.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a configurational diagram of a flying body according to thepresent embodiment;

FIG. 2 shows a list of a plurality of operational modes of the PCU ofFIG. 1;

FIG. 3 is a state transition diagram of the flying body of FIG. 1;

FIG. 4 is a flow chart showing processing of the PCU of FIG. 1;

FIG. 5 is a flow chart showing the details of the failure mode of FIG.4;

FIG. 6 is a flow chart showing the details of the engine malfunctionmode of FIG. 5;

FIG. 7 is a flow chart showing the details of the clutch malfunctionmode of FIG. 5;

FIG. 8 is a flow chart showing the details of the clutch malfunctionmode of FIG. 5;

FIG. 9 is a flow chart showing the details of the motor generatormalfunction mode of FIG. 5;

FIG. 10 is a flow chart showing the details of the battery malfunctionmode of FIG. 5;

FIG. 11 shows a list of multiple failure modes of FIG. 5;

FIG. 12 shows operational modes corresponding to the double failurestates of FIG. 11; and

FIG. 13 is a flow chart showing the details of the low-SOC mode of FIG.4.

DESCRIPTION OF EMBODIMENTS

Preferred embodiments of a flying body according to the presentinvention will be presented and described below with reference to theaccompanying drawings.

1. Configuration of the Present Embodiment

As shown in FIG. 1, a flying body 10 according to the present embodimentis applied to a manned vertical take-off and landing aircraft, andincludes a propulsion propeller 12 (first propeller) that propels amachine body and an electric floatation propeller 14 (second propeller)that causes the machine body to float. FIG. 1 shows a case in which theflying body 10 includes one propulsion propeller 12 and a plurality offloatation propellers 14. In the present embodiment, the flying body 10may include at least one propulsion propeller 12 and at least onefloatation propeller 14. Accordingly, the present embodiment isapplicable to a flying body including a plurality of propulsionpropellers 12 and a plurality of flotation propellers 14, as well as toa flying body that includes a plurality of propulsion propellers 12 andone floatation propeller 14.

The flying body 10 includes, as a drive mechanism for driving thepropulsion propeller 12, an engine 16, a motor generator 18 connected tothe propulsion propeller 12, and a clutch 21 that connects anddisconnects the engine 16 and the motor generator 18. Here, the engine16, the clutch 21, and the motor generator 18 are arranged in the statedorder from the engine 16 toward the propulsion propeller 12.

In the flying body 10, due to the connection or disconnection by theclutch 21, at least one of the engine 16 and the motor generator 18functions as a drive source of the propulsion propeller 12 to rotate thepropulsion propeller 12. Accordingly, the flying body 10 is a flyingbody with a hybrid configuration for the propulsion propeller 12including two types of drive sources: the engine 16 and the motorgenerator 18. Furthermore, the flying body 10 includes a plurality ofmotors 24 serving as drive sources for rotating the plurality offloatation propellers 14.

The configurations of the engine 16, the motor generator 18, the clutch21, and the plurality of motors 24 are widely known, and thereforedetailed descriptions thereof are omitted here. Furthermore, in thepresent embodiment, the engine 16 is a broad concept including variousengines such as a reciprocating engine, a rotary engine, and a gasturbine engine.

The flying body 10 further includes a machine body state detectionsensor group 26, an environment state detection sensor group 28, amanipulation apparatus 30, a PCU (power control unit) 32, an outputapparatus 34, and a battery 36.

The machine body state detection sensor group 26 includes varioussensors that sequentially detect the states of various types ofdetection targets included in the flying body 10 and output thesedetection results to the PCU 32.

Specifically, the sensors relating to the engine 16 include varioussensors that detect the rotational velocity, temperature (exhausttemperature, cooling water temperature, lubricating oil temperature,fuel temperature), pressure (cooling water pressure, oil pressure, fuelpressure, in-cylinder pressure), air-fuel ratio, and injector and sparkplug voltages of the engine 16.

The sensors relating to the motor generator 18 and the motors 24 includevarious sensors that detect the rotational velocity, temperature (statortemperature, magnet temperature, switching element temperature), andcoil voltage and current.

The sensors relating to the clutch 21 include various sensors thatdetect the rotational velocity on the engine 16 side, the rotationalvelocity of the motor generator 18 side, and the hydraulic pressure ofthe valve controlling the clutch 21.

The sensors relating to the battery 36 include various sensors thatdetect the SOC (State Of Charge), voltage, temperature, and the like.

The environment state detection sensor group 28 includes various sensorsthat detect the surrounding environment of the flying body 10 and outputthese detection results to the PCU 32. The environment state detectionsensor group 28 includes various sensors that detect the outsideatmosphere temperature, the altitude of the flying body 10, and thelike, for example.

The manipulation apparatus 30 is a control stick or handle forinstructing the PCU 32 to put the flying body 10 into a desired state(operational state or flying state), by being manipulated by a rider whois riding on the flying body 10. Accordingly, the manipulation apparatus30 issues instructions to the PCU 32 for the output (necessary output orrequested output) needed for the propulsion propeller 12 and thefloatation propellers 14. The output apparatus 34 is a display apparatusor an audio apparatus such as a speaker, and outputs determinationresults or the like by the PCU 32 to the outside.

The battery 36 supplies electrical power to each section of the flyingbody 10, via the PCU 32. Furthermore, when power is generated by themotor generator 18, this generated power charges the battery 36 via thePCU 32. In FIG. 1, the flow of signals is indicated by thin arrows, andthe flow of electrical power supply is indicated by thick solid lines.

The PCU 32 functions as a control section of the flying body 10, byexecuting a program stored in a memory 38 inside this PCU 32.Essentially, the PCU 32 controls the engine 16, the clutch 21, and themotor generator 18 to rotate the propulsion propeller 12 and controlsthe motors 24 to rotate the floatation propellers 14, based oninstructions (requested power output) from the manipulation apparatus 30and the detection results of the machine body state detection sensorgroup 26 and environment state detection sensor group 28. Furthermore,the PCU 32 controls the supply of electrical power from the battery 36to each section of the flying body 10 and the charging of the battery 36when the motor generator 18 functions as a power generator. The detailsof this control method are described further below.

2. Operational Modes of the Propulsion Propeller 12

The PCU 32 has a plurality of operational modes relating to thepropulsion propeller 12 when at least one of the engine 16 and the motorgenerator 18 is used as a drive source for this propulsion propeller 12.The plurality of operational modes are stored in the memory 38 in thePCU 32, for example. FIG. 2 shows a list of a plurality of operationalmodes. The PCU 32 (see FIG. 1) selects one operational mode from amongthe plurality of operational modes, according to the state of the flyingbody 10, and controls the engine 16, the clutch 21, and the motorgenerator 18 in accordance with the selected operational mode. The PCU32 can recognize the state of the flying body 10 and the requiredoutput, based on the instructions from the manipulation apparatus 30,the detection results of the machine body state detection sensor group26, and the detection results of the environment state detection sensorgroup 28.

Here, the plurality of operational modes are an engine drive mode (alsoreferred to below as mode A), a motor drive mode (also referred to belowas mode B), an engine and motor drive mode (also referred to below asmode C), a power generation and engine drive mode (also referred tobelow as mode D), and a stop mode (also referred to below as mode E).

Mode A is an operational mode for realizing a flight state with highenergy conversion efficiency for the propulsion propeller 12, bydirectly driving the propulsion propeller 12 with the engine 16.Essentially, mode A is an operational mode for realizing a flight statethat is highly cost-efficient. In mode A, the clutch 21 is in aconnected state (ON) and the motor generator 18 is in an idle state.Therefore, the engine 16 acting as the drive source causes thepropulsion propeller 12 to rotate via the clutch 21 and the motorgenerator 18 that is in the idle state. Accordingly, in mode A, themotor generator 18 transmits the output of the engine 16 as-is to thepropulsion propeller 12.

Mode B is an operational mode for realizing a flight state in which therotational control of the propulsion propeller 12 can be easilyachieved, with relatively low noise, by stopping the driving of theengine 16 and driving the propulsion propeller 12 with the motorgenerator 18. Essentially, mode B is an operational mode for realizing aflight state with high controllability and responsivity. In mode B, theclutch 21 is in the disconnected state (OFF). Therefore, only the motorgenerator 18 acts as a drive source, and directly rotates the propulsionpropeller 12.

Mode C is an operational mode for realizing a flight state in which theengine 16 and the motor generator 18 both serve as the drive source todrive the propulsion propeller 12, thereby achieving a relatively highoutput. Essentially, mode C is an operational mode for realizing aflight state with good cost-efficiency. In mode C, the clutch 21 is inthe connected state. Therefore, the engine 16 rotates the propulsionpropeller 12 via the clutch 21, and the motor generator 18 directlyrotates the propulsion propeller 12. As a result, it is possible torotate the propulsion propeller 12 with the output of the engine 16 andto, according to the required output, provide assistance to the outputof the engine 16 with the motor generator 18.

Mode D is an operational mode for realizing a flight state in which thepropulsion propeller 12 is directly driven by the engine 16, and themotor generator 18 generates electrical power. In mode D, the clutch 21is in the connected state. Therefore, the engine 16 serving as the drivesource rotates the propulsion propeller 12 via the clutch 21, and themotor generator 18 is caused to function as a power generator, by usingthe output of the engine 16. As a result, it is possible to rotate thepropulsion propeller 12 with the output of the engine 16 and to,according to the required output, cause the motor generator 18 togenerate electrical power.

Mode E is an operational mode in which the engine 16 and the motorgenerator 18 are stopped, thereby stopping the rotation of thepropulsion propeller 12. In mode E, the clutch 21 may be in either theconnected state or the disconnected state.

As described in detail further below, in mode E, the plurality offloatation propellers 14 are rotated by being driven by the plurality ofmotors 24. In such a case, the flying body 10 floats up or hovers in theair in a low-noise state.

3. Basic Operation of the Flying Body 10

The following describes the basic operation of the flying body 10, whilereferencing the state transition diagram of FIG. 3. FIG. 3 shows thetransitions among a series of state, such as landing, lift-off, andforward/backward flying of the flying body 10 (see FIG. 1). Thedescription concerning FIG. 3 deals mainly with the transitions amongstates (operational state and flying state) of the flying body 10, andthere are cases where descriptions of the operations of individualconfigurational elements forming the flying body 10 are simplified oromitted. Furthermore, the actor performing control in this statetransition diagram is the PCU 32.

First, in a “grounded” state (also referred to below as a “parked”state), the flying body 10 is resting on the ground. The transition lineT1 indicates a case where the flying body 10 remains in the parkedstate. Here, when the rider gets on the flying body 10 and manipulatesthe manipulation apparatus 30 to provide instructions for lift-off tothe PCU 32, the flying body 10 rises up from the ground and transitionsto the “lift-off” state, as shown by the transition line T2. After this,as shown by the transition line T3, the flying body 10 rises up to atarget altitude by maintaining the lift-off state.

Next, after the flying body 10 has reached the target altitude, when therider manipulates the manipulation apparatus 30 to provide instructionsfor hovering flight to the PCU 32, the flying body 10 transitions tohovering flight, as shown by the transition line T4. As shown by thetransition line T5, in a case where the hovering flight is maintained,the PCU 32 controls each section in the flying body 10 to keep thevelocity at 0. The PCU 32 maintains the hovering flight by controllingthe roll angle, pitch angle, yaw rate, and altitude of the flying body10.

Next, in a case where the rider manipulates the manipulation apparatus30 to provide instructions for forward/backward flight (flying forwardsor backwards) of the flying body 10 to the PCU 32, the flying body 10transitions to a flight state (also referred to below as transitionalflight) for transitioning from hovering flight to forward/backwardflight at the target altitude, as shown by the transition line T6.During transitional flight, the flying body 10 remains in the state ofthe transition line T7. The flying body 10 is also capable oftransitioning from the lift-off state to the transitional flight, asshown by the transition line T8.

After this, when the rider manipulates the manipulation apparatus 30 toprovide instructions for acceleration flight of the flying body 10 tothe PCU 32, the flight state transitions from the transitional flight to“forward/backward accelerating movement”, as shown by the transitionline T9. Forward/backward accelerating movement refers to the flyingbody 10 moving forward or backward while accelerating, at the targetaltitude. In a case where the forward/backward accelerating movementflight state is maintained, the state indicated by the transition lineT10 continues.

After this, when the rider manipulates the manipulation apparatus 30 toprovide instructions for constant velocity flight of the flying body 10to the PCU 32, a transition is made from the forward/backwardaccelerating movement to a constant velocity flight state of“forward/backward movement”, as shown by the transition line T11. In thefollowing description, the “forward/backward movement” of the constantvelocity flight may be referred to as “forward/backward movement withsubstantially constant velocity”. Furthermore, when the ridermanipulates the manipulation apparatus 30 to provide instructions fordeceleration flight of the flying body 10 to the PCU 32, a transition ismade from the forward/backward accelerating movement to a flight stateof “forward/backward decelerating movement”, as shown by the transitionline T12. The forward/backward decelerating movement refers to theflying body 10 moving forward or backward while decelerating, at thetarget altitude.

In each type of flight state having forward/backward movement at thetarget altitude, which are the “forward/backward movement”,“forward/backward accelerating movement”, and “forward/backwarddecelerating movement”, it is possible to transition to another one ofthese flight states in response to the manipulation of the manipulationapparatus 30 by the rider, as shown by transition lines T13 to T16. In acase where the “forward/backward movement” flight state is maintained,the state of the transition line T17 is maintained. In a case where the“forward/backward decelerating movement” flight state is maintained, thestate of the transition line T18 is maintained.

After this, when the rider manipulates the manipulation apparatus 30 toprovide instructions for vertical flight of the flying body 10 to thePCU 32, the flying body 10 transitions to a flight state fortransitioning from the forward/backward decelerating movement flightstate to a vertical flight state, as shown by the transition line T19.In the description below, this state transition is also referred to as“transitional flight”. In a case where this transitional flight ismaintained, the state of the transition line T20 is maintained.

After this, according to a manipulation of the manipulation apparatus 30by the rider, the flying body 10 transitions from the transitionalflight to the hovering flight, as shown by the transition line T21, ortransitions from the transitional flight to the “landing” state to landon the ground from the target altitude, as shown by the transition lineT22. In the case where the transition to the hovering flight is made,after this, when the rider manipulates the manipulation apparatus 30 toprovide instructions for landing, the flying body 10 transitions fromthe hovering flight to the “landing” state, as shown by the transitionline T23. In a case where “landing” is maintained, the state of thetransition line 124 is maintained.

When the flying body 10 lands on the ground, the flying body 10transitions from the landing flight to the grounded (parked) state, asshown by the transition line T25. Furthermore, the flying body 10 cantransition from the landing flight to the lift-off flight, as shown bythe transition line T26, in response to a manipulation of themanipulation apparatus 30 by the rider.

In FIG. 3, in the “lift-off”, “hovering flight”, and “landing”operational states (flight states), the PCU 32 (see FIG. 1) controls theplurality of motors 24 to rotate the plurality of floatation propellers14, to cause the flying body 10 to fly vertically. Furthermore, in the“forward/backward movement”, “forward/backward accelerating movement”,and “forward/backward decelerating movement” operational states (flightstates), the PCU 32 controls the engine 16, the clutch 21, and the motorgenerator 18 to rotate the propulsion propeller 12, to cause the flyingbody 10 to fly forward/backward. Furthermore, in the two “transitionalflight” operational states, a transition is made from the verticalflight realized by the floatation propellers 14 to the forward/backwardflight realized by the propulsion propeller 12 or from theforward/backward flight realized by the propulsion propeller 12 to thevertical flight realized by the floatation propellers 14.

4. Flight Control of the Flying Body 10 by the PCU 32

The following describes flight control of the flying body 10 by the PCU32, while referencing FIGS. 4 to 13. Here, a case is described in whichthe PCU 32 selects a suitable operational mode from among the pluralityof operational modes, according to the state of the flying body 10, and,in accordance with the selected operational mode, controls the engine16, the clutch 21, and the motor generator 18 to rotate the propulsionpropeller 12 and controls the motors 24 to rotate the floatationpropellers 14. The control for the engine 16, the clutch 21, and themotor generator 18 and the control for the plurality of motors 24 ineach operational mode, as well as operations of the propulsion propeller12 and the plurality of flotation propellers 14 due to these controls,have already been described in relation to FIG. 2. Therefore, thefollowing description focuses mainly on the method by which the PCU 32selects the operational mode.

4.1 Control in a Normal State

First, control of the flying body 10 by the PCU 32 in a case where theflying body 10 is in a normal state will be described, while referencingFIG. 4. A normal state refers to a state in which the SOC is greaterthan or equal to a threshold value and failures such as a malfunction orabnormality have not occurred in the flying body 10, for example.

At step S1 of FIG. 4, the PCU 32 (see FIG. 1) judges whether a systemerror (failure) such as a malfunction or abnormality has occurred ineach section of the flying body 10, based on the detection results ofthe machine body state detection sensor group 26 and the environmentstate detection sensor group 28. A system error refers to a failure indetection targets (e.g., the engine 16) of the machine body statedetection sensor group 26 and the environment state detection sensorgroup 28.

At step S1, if there is a system error (step S1: NO), the process movesto the failure mode of step S2. The process performed in the failuremode is described in FIGS. 5 to 12.

On the other hand, at step S1, if there is no system error (step S1:YES), the PCU 32 moves to step S3 and judges whether the SOC of thebattery 36 is greater than or equal to the threshold value or not, basedon the detection results of the machine body state detection sensorgroup 26.

At step S3, if the SOC is less than the threshold value (step S3: NO),the PCU 32 judges the SOC to be insufficient and moves to the low-SOCmode of step S4. The processing in the low-SOC mode is described in FIG.13.

On the other hand, at step S3, if the SOC is greater than or equal tothe threshold value (step S3: YES), the PCU 32 moves to step S5 andjudges whether the current operational state (flight state) of theflying body 10 is lift-off, hovering flight, or landing or not, based oninstructions from the manipulation apparatus 30 and detection results ofthe machine body state detection sensor group 26 and the environmentstate detection sensor group 28.

At step S5, if the flight state is lift-off, hovering flight, or landing(step S5: YES), the PCU 32 moves to step S6, selects mode E (see FIG. 2)by referencing the memory 38, and drives (turns ON) the motors 24.

At step S5, if the flight state is not lift-off, hovering flight, orlanding (step S5: NO), the PCU 32 moves to step S7 and judges whetherthe current flight state is transitional flight.

At step S7, if the flight state is transitional flight (step S7; YES),the PCU 32 moves to step S8, selects mode B by referencing the memory38, and drives the motors 24.

At step S7, if the flight state is not transitional flight (step S7:NO), the PCU 32 moves to step S9 and judges whether the current flightstate is forward/backward accelerating movement.

At step S9, if the flight state is forward/backward acceleratingmovement (step S9: YES), the PCU 32 moves to step S10, selects mode C byreferencing the memory 38, and stops (turns OFF) the driving of themotors 24.

At step S9, if the flight state is not forward/backward acceleratingmovement (step S9: NO), the PCU 32 moves to step S11 and judges whetherthe current flight state is forward/backward movement with substantiallyconstant velocity.

At step S11, if the flight state is forward/backward movement withsubstantially constant velocity (step S11: YES), the PCU 32 moves tostep S12, selects mode A by referencing the memory 38, and stops thedriving of the motors 24.

At step S11, if the flight state is not forward/backward movement withsubstantially constant velocity (step S11: NO), the PCU 32 moves to stepS13 and judges whether the current flight state is backward/forwarddecelerating movement.

At step S13, if the flight state is backward/forward deceleratingmovement (step S13: YES), the PCU 32 moves to step S14, selects mode Dby referencing the memory 38, and stops the driving of the motors 24.

At step S13, if the flight state is not backward/forward deceleratingmovement (step S13: NO), the PCU 32 moves to step S15, judges that thecurrent flight state is the parking mode (grounded state of FIG. 2),selects mode E by referencing the memory 38, and stops the driving ofthe motors 24.

In this way, in a case where the flying body 10 is in a normal state,the PCU 32 basically selects a suitable operational mode from the memory38 according to the corresponding flight state. Due to this, the PCU 32controls the engine 16, the clutch 21, and the motor generator 18 torotate the propulsion propeller 12, in accordance with the selectedoperational mode, and controls the motors 24 to rotate the floatationpropellers 14.

4.2 Control in the Failure Mode

The following describes control of the PCU 32 in a case where the flyingbody 10 is in a malfunctioning state or abnormal state (failure mode),while referencing FIG. 5.

At step S21 of FIG. 5, the PCU 32 (see FIG. 1) judges whether a systemerror such as a malfunction of the flying body 10 is a single failurestate at a single location, based on the detection results of themachine body state detection sensor group 26 and the environment statedetection sensor group 28. If the system error is a single failure state(step S21: YES), the process moves to step S22.

At step S22, the PCU 32 judges whether the single failure is amalfunction of a floatation propeller 14. In such a case, the judgmentconcerning whether there is a malfunction in the floatation propeller 14is made based on the rotational velocity, temperature (statortemperature, magnet temperature, or switching element temperature), andcoil voltage and current of the motor 24 driving the floatationpropeller 14. If there is a malfunction in the floatation propeller 14(step S22: YES), the process moves to step S23. At step S23, the PCU 32transitions to a floatation propeller malfunction mode, and since thefloatation propeller 14 is malfunctioning, controls each section of theflying body 10 to land the flying body 10.

At step S22, if the floatation propeller 14 is not malfunctioning (stepS22: NO), the PCU 32 moves to step S24 and judges whether the singlefailure is a malfunction in the engine 16. In this case, the judgementof whether there is a malfunction in the engine 16 is made based on therotational velocity, the temperature (exhaust temperature, cooling watertemperature, lubricating oil temperature, or fuel temperature), pressure(cooling water pressure, oil pressure, fuel pressure, in-cylinderpressure), air-fuel ratio, and injector and spark plug voltages of theengine 16. If there is a malfunction in the engine 16 (step S24: YES),the PCU 32 moves to step S25, transitions to the engine malfunctionmode, and performs control of each section of the flying body 10corresponding to the malfunction of the engine 16. The details of theengine malfunction mode are described in FIG. 6.

At step S24, if there is no malfunction in the engine 16 (step S24: NO),the PCU 32 moves to step S26 and judges whether the single failure is amalfunction in the clutch 21. In such a case, the judgment of whetherthere is a malfunction in the clutch 21 is made based on the rotationalvelocity of the clutch 21 on the engine 16 side, the rotational velocityof the clutch 21 on the motor generator 18 side, and the hydraulicpressure of the valve controlling the clutch 21. If there is amalfunction in the clutch 21 (step S26: YES), the PCU 32 moves to stepS27, transitions to a clutch malfunction mode, and performs control ofeach section of the flying body 10 corresponding to the malfunction inthe clutch 21. The details of the clutch malfunction mode are describedin FIGS. 7 and 8.

At step S26, if there is no malfunction in the clutch 21 (step S26: NO),the PCU 32 moves to step S28 and judges whether the single failure is amalfunction in the motor generator 18. In such a case, the judgmentconcerning whether there is a malfunction in the motor generator 18 ismade based on the rotational velocity, temperature (stator temperature,magnet temperature, or switching element temperature), and coil voltageand current of the motor generator 18. If there is a malfunction in themotor generator 18 (step S28: YES), the PCU 32 moves to step S29,transitions to a motor generator malfunction mode, and performs controlof each section of the flying body 10 corresponding to the malfunctionin the motor generator 18. The details of the motor generatormalfunction mode are described in FIG. 9.

At step S28, if there is no malfunction in the motor generator 18 (stepS28: NO), the PCU 32 moves to step S30, judges that the single failureis a malfunction in the battery 36, transitions to a battery malfunctionmode, and performs control of each section of the flying body 10corresponding to the malfunction in the battery 36. The details of thebattery malfunction mode are described in FIG. 10. The PCU 32 may makethe judgment about the malfunction in the battery 36 based on the SOC,voltage, temperature, and the like of the battery 36.

At step S21, if the system error is not a single failure (step S21: NO),the PCU 32 judges that there is a multiple failure of abnormalities ormalfunctions at two or more locations, and moves to step S31. At stepS31, the PCU 32 transitions to a multiple failure mode, and performscontrol of each section of the flying body 10 corresponding to themalfunctions at a plurality of locations. The details of the multiplefailure mode are described in FIGS. 11 and 12.

The following describes the details of each malfunction mode and themultiple failure mode, in order.

4.2.1 Engine Malfunction Mode

The details of the engine malfunction mode are described whilereferencing FIG. 6.

First, at step S41 of FIG. 6, the PCU 32 (see FIG. 1) providesnotification about the malfunctioning of the engine 16 to the outside,via the output apparatus 34. For example, if the output apparatus 34 isa display apparatus, the PCU 32 displays information indicating that theengine 16 is malfunctioning on a screen of the display apparatus, towarn the rider.

Next, at step S42, the PCU 32 judges whether the current operationalstate (flight state) of the flying body 10 is lift-off, hovering flight,or landing or not. If the flight state is lift-off, hovering flight, orlanding (step S42: YES), the PCU 32 moves to step S43, selects mode E(see FIG. 2) by referencing the memory 38, and drives (turns ON) themotors 24.

At step S42, if the flight state is not lift-off, hovering flight, orlanding (step S42: NO), the PCU 32 moves to step S44 and judges whetherthe current flight state is transitional flight, based on instructionsfrom the manipulation apparatus 30 and detection results of the machinebody state detection sensor group 26 and the environment state detectionsensor group 28.

At step S44, if the flight state is transitional flight (step S44: YES),the PCU 32 moves to step S45, selects mode B by referencing the memory38, and drives the motors 24.

At step S44, if the flight state is not transitional flight (step S44:NO), the PCU 32 moves to step S46 and judges whether the current flightstate is a type of forward/backward movement (forward/backwardaccelerating movement, forward/backward movement with a substantiallyconstant velocity, or forward/backward decelerating movement).

At step S46, if the flight state is any type of forward/backwardmovement (step S46: YES), the PCU 32 moves to step S47, selects mode Bby referencing the memory 38, and stops (turns OFF) the driving of themotors 24.

At step S46, if the flight status is none of the types offorward/backward movement (step S46: NO), the PCU 32 moves to step S48,judges that the current flight state is the parking mode (grounded stateof FIG. 2), selects mode E by referencing the memory 38, and stops thedriving of the motors 24.

In this way, in a case where the flying body 10 is in the enginemalfunction mode, the PCU 32 drives the motor generator 18 to rotate thepropulsion propeller 12 when there is transitional flight or any type offorward/backward movement (mode B of steps S45 and S47). Therefore, thePCU 32 can control the clutch 21 to rotate the propulsion propeller 12,in accordance with the selected operational mode, and control the motors24 to rotate the floatation propellers 14.

4.2.2 Clutch Malfunction Mode

The details of the clutch malfunction mode are described whilereferencing FIGS. 7 and 8.

First, at step S51 of FIG. 7, the PCU 32 (see FIG. 1) judges whether themalfunction in the clutch 21 is a malfunction (ON malfunction) ofremaining in the connected state despite instruction for disconnectionbeing issued from the PCU 32 to the clutch 21. If the malfunction is anON malfunction (step S51: YES), the PCU 32 moves to step S52 andprovides notification (warning display) that the clutch 21 has an ONmalfunction to the rider, via the output apparatus 34.

Next, at step S53, the PCU 32 judges whether the current operationalstate (flight state) of the flying body 10 is lift-off, hovering flight,or landing or not. If the flight state is lift-off, hovering flight, orlanding (step S53: YES), the PCU 32 moves to step S54, selects mode E(see FIG. 2) by referencing the memory 38, and drives (turns ON) themotors 24.

At step S53, if the flight state is not lift-off, hovering flight, orlanding (step S53: NO), the PCU 32 moves to step S55 and judges whetherthe current flight state is transitional flight, based on instructionsfrom the manipulation apparatus 30 and detection results of the machinebody state detection sensor group 26 and the environment state detectionsensor group 28.

At step S55, if the flight state is transitional flight (step S55: YES),the PCU 32 moves to step S56, selects mode C by referencing the memory38, and drives the motors 24.

At step S55, if the flight state is not transitional flight (step S55:NO), the PCU 32 moves to step S57 and judges whether the current flightstate is forward/backward accelerating movement.

At step S57, if the flight state is forward/backward acceleratingmovement (step S57: YES), the PCU 32 moves to step S58, selects mode Cby referencing the memory 38, and stops (turns OFF) the driving of themotors 24.

At step S57, if the flight state is not forward/backward acceleratingmovement (step S57: NO), the PCU 32 moves to step S59 and judges whetherthe current flight state is forward/backward movement with substantiallyconstant velocity.

At step S59, if the flight state is forward/backward movement withsubstantially constant velocity (step S59: YES), the PCU 32 moves tostep S60, selects mode A by referencing the memory 38, and stops thedriving of the motors 24.

At step S59, if the flight state is not forward/backward movement withsubstantially constant velocity (step S59: NO), the PCU 32 moves to stepS61 and judges whether the current flight state is backward/forwarddecelerating movement.

At step S61, if the flight state is backward/forward deceleratingmovement (step S61: YES), the PCU 32 moves to step S62, selects mode Dby referencing the memory 38, and stops the driving of the motors 24.

At step S61, if the flight state is not forward/backward deceleratingmovement (step S61: NO), the PCU 32 moves to step S63, judges that thecurrent flight state is the parking mode, selects mode E by referencingthe memory 38, and stops the driving of the motors 24.

In this way, in the case of the ON malfunction of the clutch 21, the PCU32 rotates the propulsion propeller 12 in an operational mode using theoutput of the engine 16 or causes the motor generator 18 to generateelectrical power, when there is transitional flight or any type offorward/backward movement (modes C, A, and D of steps S56, S58, S60, andS62). In this case as well, the PCU 32 can control the engine 16 and themotor generator 18 to rotate the propulsion propeller 12, in accordancewith the selected operational mode, and control the motors 24 to rotatethe floatation propellers 14.

On the other hand, at step S51, if the malfunction of the clutch 21 is amalfunction (OFF malfunction) of not transitioning to the connectedstate despite instruction for connection being issued from the PCU 32 tothe clutch 21 (step S51: NO), the process moves to step S71 of FIG. 8.At step S71, the PCU 32 (see FIG. 1) provides notification (warningdisplay) that the clutch 21 has an OFF malfunction to the rider, via theoutput apparatus 34.

Next, at step S72, the PCU 32 judges whether the current operationalstate (flight state) of the flying body 10 is lift-off, hovering flight,or landing or not. If the flight state is lift-off, hovering flight, orlanding (step S72: YES), the PCU 32 moves to step S73, selects mode E(see FIG. 2) by referencing the memory 38, and drives (turns ON) themotors 24.

At step S72, if the flight state is not lift-off, hovering flight, orlanding (step S72: NO), the PCU 32 moves to step S74 and judges whetherthe current flight state is transitional flight, based on instructionsfrom the manipulation apparatus 30 and detection results of the machinebody state detection sensor group 26 and the environment state detectionsensor group 28.

At step S74, if the flight state is transitional flight (step S74; YES),the PCU 32 moves to step S75, selects mode B by referencing the memory38, and drives the motors 24.

At step S74, if the flight state is not transitional flight (step S74:NO), the PCU 32 moves to step S76 and judges whether the current flightstate is a type of forward/backward movement.

At step S76, if the flight state is any type forward/backward movement(step S76: YES), the PCU 32 moves to step S77, selects mode B byreferencing the memory 38, and stops (turns OFF) the driving of themotors 24.

At step S76, if the flight state is not any type of forward/backwardmovement (step S76: NO), the PCU 32 moves to step S78, judges that thecurrent flight state is the parking mode, selects mode E by referencingthe memory 38, and stops the driving of the motors 24.

In this way, in the case of the OFF malfunction of the clutch 21, thePCU 32 rotates the propulsion propeller 12 with an operational modeusing the output of the motor generator 18 when there is transitionalflight or any type of forward/backward movement (mode B of steps S75 andS77). In this case as well, the PCU 32 can control the motor generator18 to rotate the propulsion propeller 12, in accordance with theselected operational mode, and control the motors 24 to rotate thefloatation propellers 14.

4.2.3 Motor Generator Malfunction Mode

The details of the motor generator malfunction mode are described whilereferencing FIG. 9.

First, at step S81 of FIG. 9, the PCU 32 (see FIG. 1) providesnotification (warning display) that the motor generator 18 ismalfunctioning to the outside, via the output apparatus 34.

Next, at step S82, the PCU 32 judges whether the current operationalstate (flight state) of the flying body 10 is lift-off, hovering flight,or landing or not. If the flight state is lift-off, hovering flight, orlanding (step S82: YES), the PCU 32 moves to step S83, selects mode E(see FIG. 2) by referencing the memory 38, and drives (turns ON) themotors 24.

At step S82, if the flight state is not lift-off, hovering flight, orlanding (step S82: NO), the PCU 32 moves to step S84 and judges whetherthe current flight state is transitional flight, based on instructionsfrom the manipulation apparatus 30 and detection results of the machinebody state detection sensor group 26 and the environment state detectionsensor group 28.

At step S84, if the flight state is transitional flight (step S84; YES),the PCU 32 moves to step S85, selects mode A by referencing the memory38, and drives the motors 24. In this case, the malfunctioning motorgenerator 18 is in an idle state, and the output of the engine 16 istransmitted as-is to the propulsion propeller 12.

At step S84, if the flight state is not transitional flight (step S84:NO), the PCU 32 moves to step S86 and judges whether the current flightstate is a type of forward/backward movement.

At step S86, if the flight state is any type forward/backward movement(step S86: YES), the PCU 32 moves to step S87, selects mode A byreferencing the memory 38, and stops (turns OFF) the driving of themotors 24. In this case as well, in the same manner as in step S85, themotor generator 18 that is malfunctioning is in the idle state, and theoutput of the engine 16 is transmitted as-is to the propulsion propeller12.

At step S86, if the flight state is not any type of forward/backwardmovement (step S86: NO), the PCU 32 moves to step S88, judges that thecurrent flight state is the parking mode, selects mode E by referencingthe memory 38, and stops the driving of the motors 24.

In this way, in a case where the flying body 10 is in the motorgeneration malfunction mode, the PCU 32 drives the engine 16 to rotatethe propulsion propeller 12 when there is transitional flight or anytype of forward/backward movement (mode A of steps S85 and S87).Therefore, the PCU 32 can control the clutch 21 to rotate the propulsionpropeller 12, in accordance with the selected operational mode, andcontrol the motors 24 to rotate the floatation propellers 14.

4.2.4 Battery Malfunction Mode

Details of the battery malfunction mode are described while referencingFIG. 10.

First, at step S91 of FIG. 10, the PCU 32 (see FIG. 1) providesnotification (warning display) that the battery 36 is malfunctioning tothe outside, via the output apparatus 34.

Next, at step S92, the PCU 32 judges whether the current operationalstate (flight state) of the flying body 10 is lift-off, hovering flight,or transitional flight from vertical flight to backward/forward movementor not. If the flight state is lift-off, hovering flight, or thistransitional flight (step S92: YES), the PCU 32 moves to step S93,transitions to the landing mode, and causes the flying body 10 to land.

At step S92, if the flight state is not lift-off, hovering flight, orthe transitional flight above (step S92: NO), the PCU 32 moves to stepS94 and judges whether the current flight state is a type offorward/backward movement, based on instructions from the manipulationapparatus 30 and detection results of the machine body state detectionsensor group 26 and the environment state detection sensor group 28.

At step S94, if the flight state is any type of forward/backwardmovement (step S94: YES), the PCU 32 moves to step S95, selects mode A(see FIG. 2) by referencing the memory 38, and stops driving of themotors 24.

At step S94, if the flight state is not any type of forward/backwardmovement (step S94: NO), the PCU 32 moves to step S96 and judges whetherthe current flight state is a transitional flight from backward/forwardmovement to vertical movement or a landing flight or not.

At step S96, if the flight state is the transitional flight describedabove or the landing flight (step S96: YES), the PCU 32 moves to stepS97, selects mode D by referencing the memory 38, and drives the motors24.

At step S96, if the flight state is not the above transitional flight orthe landing flight (step S96: NO), the PCU 32 moves to step S98, judgesthat the current flight state is the parking mode, selects mode E byreferencing the memory 38, and stops the driving of the motors 24.

In this way, in a case where the flying body 10 is in the batterymalfunction mode, since the power cannot be supplied from the battery 36to each section of the flying body 10, the PCU 32 causes the motorgenerator 18 to generate electrical power using the output of the engine16 and supplies the generated power to the motors 24 to drive thesemotors 24, when the motors 24 are controlled to rotate the floatationpropellers 14 (mode D of step S97).

In this case as well, the PCU 32 can control the clutch 21 to rotate thepropulsion propeller 12 and control the motors 24 to rotate thefloatation propellers 14, in accordance with the selected operationalmode.

4.2.5 Multiple Failure Mode

The details of the multiple failure mode are described while referencingFIGS. 11 and 12. Here, as an example, a case is described of a doublefailure, in which malfunctions occur within the flying body 10 at twolocations.

As shown in FIG. 11, with a double failure, malfunctions occur inconfigurational elements at two locations among the engine 16, theclutch 21, and the motor generator 18. In FIG. 11, such examples ofdouble failures are indicated by (1) to (5). As shown in FIG. 12, foreach of the double failures (1) to (5), the PCU 32 (see FIG. 1) selectsthe operational modes indicated in the middle cells and the bottom cellsto control the motors 24, according to the states shown in the topcells.

In the multiple failure mode, if the occurrences of two different doublefailures are detected at different times, the PCU 32 prioritizes theselection of an operational mode corresponding to the double failuredetermined first, or selects an operational mode resulting in a greaterincrease in safety among the determined double failures.

As shown in FIG. 11, priority is determined by the columns and rows inthe chart, and in a case where the occurrences of two different doublefailures are detected at different times, the operational modecorresponding to the double failure with higher priority may beselected. For example, in a case where the two double failures (1) and(2) in FIG. 11 are detected, the PCU 32 selects the double failure (1)that has higher priority, and selects the operational mode correspondingto the selected double failure (1).

In this way, in the multiple failure mode, the operational mode isselected using a different method than in the single failure modedescribed in FIGS. 6 to 10.

4.2.6 Low-SOC Mod)

The details of the low-SOC mode are described while referencing FIG. 13.

First, at step S101 in FIG. 13, the PCU 32 (see FIG. 1) providesnotification (warning display) that the SOC is relatively low to therider, via the output apparatus 34.

Next, at step S102, the PCU 32 judges whether the current operationalstate (flight state) of the flying body 10 is lift-off, hovering flight,or landing or not. If the flight state is lift-off, hovering flight, orlanding (step S102: YES), the PCU 32 moves to step S103, selects mode E(see FIG. 2) by referencing the memory 38, and drives (turns ON) themotors 24.

At step S102, if the flight state is not lift-off, hovering flight, orlanding (step S102: NO), the PCU 32 moves to step S104 and judgeswhether the current flight state is transitional flight, based oninstructions from the manipulation apparatus 30 and detection results ofthe machine body state detection sensor group 26 and the environmentstate detection sensor group 28.

At step S104, if the flight state is the transitional flight describedabove (step S104: YES), the PCU 32 moves to step S105, selects mode D byreferencing the memory 38, and drives the motors 24.

At step S104, if the flight state is not transitional flight (step S104:NO), the PCU 32 moves to step S106 and judges whether the current flightstate is forward/backward accelerating movement.

At step S106, if the flight state is forward/backward acceleratingmovement (step S106: YES), the PCU 32 moves to step S107, selects mode Aby referencing the memory 38, and stops (turns OFF) the driving of themotors 24.

At step S106, if the flight state is not forward/backward acceleratingmovement (step S106: NO), the PCU 32 moves to step S108, and judgeswhether the current flight state is forward/backward movement with asubstantially constant velocity or forward/backward deceleratingmovement or not.

At step S108, if the flight state is forward/backward movement with asubstantially constant velocity or forward/backward deceleratingmovement (step S108: YES), the PCU 32 moves to step S109, selects mode Dby referencing the memory 38, and stops the driving of the motors 24.

At step S108, if the flight state is not forward/backward movement witha substantially constant velocity or forward/backward deceleratingmovement (step S108: NO), the PCU 32 moves to step S110, judges that thecurrent flight state is the parking mode, selects mode E by referencingthe memory 38, and stops the driving of the motors 24.

In this way, in the case of the low-SOC mode, in order to prioritizecharging the battery 36 or supplying power to the motors 24, the PCU 32causes the motor generator 18 to generate electrical power using theoutput of the engine 16 (mode D of steps S105 and S109). At this time,the PCU 32 charges the battery 36 with surplus power remaining after theamount of power needed by the motors 24 to rotate the floatationpropellers 14 is subtracted from the amount of power generated by themotor generator 18. On the other hand, in a case where the amount ofpower needed by the motors 24 cannot be covered by the amount of powergenerated by the motor generator 18, the shortfall in the power issupplied from the battery 36 to the motors 24. In this case as well, thePCU 32 can control the engine 16, the clutch 21, and the motor generator18 to rotate the propulsion propeller 12, in accordance with theselected operational mode, and control the motors 24 to rotate thefloatation propellers 14.

5. Effect of the Present Embodiment

As described above, the flying body 10 according to the presentembodiment is a flying body 10 including a propulsion propeller 12(first propeller) that propels a machine body and an electric floatationpropeller 14 (second propeller) that causes the machine body to float.The flying body 10 further includes an engine 16; a motor generator 18connected to the propulsion propeller 12; a clutch 21 that connects anddisconnects the engine 16 and the motor generator 18; and a PCU 32(control section). The PCU 32 has a plurality of operational modes inwhich at least one of the engine 16 and the motor generator 18 acts as adrive source of the propulsion propeller 12. The PCU 32 controls theengine 16, the clutch 21, and the motor generator 18 in accordance withone operational mode, among the plurality of operational modes,depending on a state of the flying body 10.

In this way, the flying body 10 includes the engine 16, the clutch 21,the motor generator 18, and the PCU 32, and has a hybrid configurationin which at least one of the engine 16 and the motor generator 18 actsas the drive source of the propulsion propeller 12. Furthermore, the PCU32 has a plurality of operational modes, and connects or disconnects theclutch 21 in an optimal operational mode, according to the state of theflying body 10.

Due to this, it is possible to make the flying body 10 fly bycontrolling the engine 16, the clutch 21, and the motor generator 18 inthe operational mode that is optimal from the viewpoints of safety,noise, comfort, controllability, and cost. As a result, it is possibleto realize a flying body 10 with a high degree of freedom of controladaptable to various situations, without adopting a complicatedconfiguration.

The flying body 10 further includes a motor 24 that acts as a drivesource of the floatation propeller 14 and a battery 36 that supplieselectrical power to each section of the flying body 10. The PCU 32selects one operational mode from among the plurality of operationalmodes, based on at least one of a presence or lack of a failure in theflying body 10 and an SOC of the battery 36, and, according to theselected operational mode, controls the engine 16, the clutch 21, andthe motor generator 18, and also controls the motor 24. In this way, itis possible to select the optimal operational mode according to thepresence or lack of a failure or the SOC. As a result, particularly in anormal state, it is possible to reduce the noise and increase thecomfort and cost-efficiency.

In this case, when the flying body 10 performs lift-off, hoveringflight, or landing, the PCU 32 controls the motor 24 to rotate thefloatation propeller 14. Due to this, it is possible to further improvethe noise reduction, comfort, and cost-efficiency.

Furthermore, in the case of the normal state, when the flying body 10transitions between lift-off, hovering flight, or landing and forward orbackward flight, the PCU 32 controls the motor 24 to rotate thefloatation propeller 14, and also sets the clutch 21 to the disconnectedstate and controls the motor generator 18 to rotate the propulsionpropeller 12. Due to this, it is possible to realize an improvement inthe noise reduction, comfort, and cost efficiency while smoothlytransitioning between vertical flight and forward or backward flight.

In a case where the SOC is less than the threshold value, when theflying body 10 performs lift-off, hovering flight, or landing, the PCU32 sets the clutch 21 to the connected state, causes the motor generator18 to generate electrical power using output of the engine 16, androtates the floatation propeller 14 by supplying the generatedelectrical power to the motor 24. In this way, since it is possible toselect the optimal operational mode according to the SOC, it is possibleto minimize the power consumption of the battery 36 in a state where theSOC is relatively low.

Furthermore, in a case where the SOC is less than the threshold value,when the flying body 10 performs transitional flight, the PCU 32 setsthe clutch 21 to the connected state, rotates the propulsion propeller12 using output of the engine 16, and the PCU 32 further causes themotor generator 18 to generate electrical power and supplies thegenerated electrical power to the motors 24 to thereby rotate thefloatation propellers 14. Due to this, it is possible to realize animprovement in the noise reduction, comfort, and cost efficiency, whilesmoothly transitioning between vertical flight and forward/backwardflight and minimizing the power consumption of the battery 36.

In this case, the PCU 32 charges the battery 36 with surplus electricalpower remaining after subtracting an electrical power amount needed forrotating the floatation propeller 14 from an electrical power amountgenerated by the motor generator 18, and, in a case where the electricalpower amount generated by the motor generator 18 cannot cover theelectrical power amount needed for rotating the floatation propeller 14,supplies this lacking electrical power amount from the battery 36 to thefloatation propeller 14. Due to this, it is possible to suitably supplyelectrical power to each section of the flying body 10 while preservingthe SOC of the battery 36.

In the case of the normal state or in a case where the SOC is less thanthe threshold value, when the flying body 10 performs forward orbackward flight, the PCU 32 sets the clutch 21 to the connected stateand causes the propulsion propeller 12 to rotate using output of theengine 16, and also, according to a necessary output of the flying body10, assists with the output of the engine 16 using the motor generator18 or causes the motor generator 18 to generate electrical power. Inthis way, since it is possible to realize hybrid driving correspondingto the presence or lack of failures and the SOC, it is possible torealize both a restriction of the power consumption of the battery 36and an improvement of the noise reduction, comfort, and cost efficiency.

In a case where a failure has occurred in the flying body 10, in orderto prioritize continuation of the flight of the flying body 10, the PCU32 selects, from among the plurality of operational modes, a failuremode (another operational mode) different from an operational mode usedin the normal state, and controls the engine 16, the clutch 21, and themotor generator 18 according to the selected failure mode. In this way,when a failure occurs, a driving mode with redundancy is selected, andtherefore it is possible to improve the safety of the flying body 10.

Here, in a case where a plurality of failures have occurred in theflying body 10, the PCU 32 selects another operational mode for amultiple failure, which is different from the operational mode used whenone failure has occurred, and controls the engine 16, the clutch 21, andthe motor generator 18 according to the selected multiple failureoperational mode. In this way, by selecting a driving mode withredundancy when a plurality of failures occur, it is possible to furtherimprove the safety of the flying body 10.

The present invention is not limited to the above-described embodiment,and it goes without saying that various modifications could be adoptedtherein without departing from the essence and gist of the presentinvention.

What is claim is:
 1. A flying body comprising a first propeller thatpropels a machine body and an electric second propeller that causes themachine body to float, the flying body further comprising: an engine; amotor generator connected to the first propeller; a clutch that connectsand disconnects the engine and the motor generator; and a controlsection that has a plurality of operational modes in which at least oneof the engine or the motor generator acts as a drive source of the firstpropeller and that controls the engine, the clutch, and the motorgenerator, in accordance with one operational mode among the pluralityof operational modes, depending on a state of the flying body.
 2. Theflying body according to claim 1, further comprising: a motor serving asa drive source of the second propeller, and a battery that supplieselectrical power to each section of the flying body, wherein: thecontrol section selects one operational mode from among the plurality ofoperational modes, based on at least one of a presence of a failure inthe flying body or a state of charge of the battery, and, according tothe selected operational mode, controls the engine, the clutch, and themotor generator, and also controls the motor.
 3. The flying bodyaccording to claim 2, wherein: the control section controls the motor torotate the second propeller when the flying body performs lift-off,hovering flight, or landing.
 4. The flying body according to claim 2,wherein: in a case of a normal state where the failure has not occurredin the flying body and the state of charge is greater than or equal to athreshold value, when the flying body transitions between lift-off,hovering flight, or landing and forward or backward flight, the controlsection controls the motor to rotate the second propeller and thecontrol section also sets the clutch to a disconnected state andcontrols the motor generator to rotate the first propeller.
 5. Theflying body according to claim 2, wherein: in a case where the state ofcharge is less than a threshold value, when the flying body transitionsbetween lift-off, hovering flight, or landing and forward or backwardflight, the control section sets the clutch to a connected state tothereby rotate the first propeller using output of the engine, andcauses the motor generator to generate electrical power and supplies thegenerated electrical power to the motor to thereby rotate the secondpropeller.
 6. The flying body according to claim 5, wherein: the controlsection charges the battery with surplus electrical power remainingafter subtracting an electrical power amount needed for rotating thesecond propeller from an electrical power amount generated by the motorgenerator, and, in a case where the electrical power amount generated bythe motor generator cannot cover the electrical power amount requiredfor rotating the second propeller, the control section supplies ashortfall in the required electrical power amount from the battery tothe second propeller.
 7. The flying body according to claim 2, wherein:in a case of a normal state where the failure has not occurred in theflying body and the state of charge is greater than or equal to athreshold value, or in a case where the state of charge is less than thethreshold value, when the flying body performs forward or backwardflight, the control section sets the clutch to a connected state andcauses the first propeller to rotate using output of the engine, andalso, according to a necessary output of the flying body, assists withthe output of the engine using the motor generator or causes the motorgenerator to generate electrical power.
 8. The flying body according toclaim 2, wherein: in a case where the flying body is in a failure state,in order to prioritize continuation of flight of the flying body, thecontrol section selects, from among the plurality of operational modes,another operational mode different from an operational mode used in anormal state where the failure has not occurred in the flying body andthe state of charge is greater than or equal to a threshold value, andcontrols the engine, the clutch, and the motor generator, according tothe selected operational mode.
 9. The flying body according to claim 8,wherein: in a case where a plurality of failures have occurred in theflying body, the control section selects another operational modedifferent from an operational mode used when one failure has occurred,and controls the engine, the clutch, and the motor generator, accordingto the selected operational mode.